Pre-emptive 600 mg oral gabapentin reduces morphine requirements and postoperative pain following non-obstetric lower abdominal surgery

Background
Postoperative pain following lower abdominal surgery is one of the most common complications reported by patients. Gabapentin given two hours before surgery as pre-emptive analgesia has been reported to reduce postoperative pain and decrease postoperative analgesia requirements. The aim of this study was to determine the effectiveness of 600 mg oral gabapentin as a pre-emptive analgesia to reduce postoperative pain and morphine requirements following nonobstetric lower abdominal surgery.

Methods
A double-blind randomized clinical trial was conducted with 72 subjects acquired by consecutive sampling from November 2019 to February 2020 at Tangerang District Hospital. Eligible subjects were randomized to two groups: placebo or 600 mg oral gabapentin two hours before skin incision. The total morphine requirements, visual analogue scale (VAS) score, first-time analgesic demand, and side effects were assessed during the first 24 hours postoperatively.

Results
The first 24-hour postoperative total morphine was higher in the placebo group (5.33 ± 1.97 mg vs. 2.47 ± 1.90 mg; P < 0.001). The pain scale at rest and movement during recovery, two hours postoperatively, and 24 hours postoperatively were significantly different between the two groups (P < 0.05). The Mann-Whitney test showed a significant difference in the first-time morphine required as rescue analgesia between the gabapentin group (161.5 [25–990] minutes) and placebo group (67.5 [10–371] minutes; P < 0.001). No significant difference was found in adverse events between the groups.

Conclusions
Following nonobstetric lower abdominal surgery, 600 mg oral gabapentin as a pre-emptive analgesia attenuates postoperative pain and reduces morphine requirements.